Firearm



March 30, 1943. F. A.MMECEK ETAI. 2,315,207

FIREARM Filed Jan. 1o; 1959 Patented Mar. 30, 1943 il" tf1 Frantisek raneek tieix Karel Janeek,

Prague-Noale, s. ova vested in the Alien Property Application January 10 1939, Serial No. 250,208

1n sin July 1s. 193s 3 Claims. (Cl. 42-76) 'I'he invention vrelates to the construction of the barrel and the corresponding projectile of a irearm which are so constructed as to secure an increased ballistic performance of the ilrearm and a complete utilisation of the propelling charge, while employing a comparatively small barrel.

The principle of this invention comprises employing a. barrel of normal construction with a normal cylindrical bore in which the projectile is loaded, said projectile being so constructed that its calibre after passing through the barrel is substantially altered ina readily removable attachment designed for the purpose and mounted on the end of the barrel, the projectile being thereby rendered ballistically more suitable for night through the air.

The essential parts of this arrangement are therefore three, namely: n

i. The normally manufactured barrel with a cylindrical bore and suitable rifiing of relatively large calibre.

2. An attachment which is fixed to the end of the barrel, is readily detachable and is so constructed that Ain it the projectile of large calibre is altered to a ballistically more advantageous projectile of smaller calibre.

3. The suitably constructed projectile which permits such alteration of its calibre.

The actual barrel employed is a normal barrel provided with riiling grooves for producing the rotation of the projectile and differs from an entirely normal barrel merely by afsuitable device at its muzzle end (screwthread, bayonet joint or the like), permitting easy detachment and fixing of the attachment.

The attachment may be made in many modiilcations according to the construction of the projectile. Said projectile is merely deformed from the diameter f the barrel bore to the final calibre by means of guiding and sealing flanges, collars or the like. In this case, the bore of the attachment merges from the barrel bore into the nal diameter of the projectile by a conical or other suitable transition. The attachment is not ried, so that the projectile leaving it has a smooth surface Without traces of riiiing, or the projectile guide is braked and the projectile is reduced either in the conical bore of the attachment or by an annular rec'ess which may be single or stepped. By employing a single knife edge or an entire system of knife edges of circular or other profile in the attachment, the guide bands of the projectile or its shell are cut up into a quantity of splinters which, due to inertia, leave the attachment after the projectile.

Due to this braking or cutting up of the projectile casing or guide bands, there is produced a considerable force which counteracts the recoil and thereby considerably reduces it.

The projectiles are advantageously so constructed that their form, length, weight and mean load correspond to the ilnal calibre, which may be substantially smaller than the bore of the barrel.

Due to the herein described arrangement, during the passage of the projectile through the barrel, an expansion of the gases occurs in the bore, said bore being substantially larger than corresponds to the size of the projectile inthe normal arrangement. Therefore, for the same maximum pressures of the gases, the force acting on the base of the projectile is increased in the proportion in which the cross-section is increased, and in the same proportion the acceleration of the projectile is also increased. An adequate expansion ratio s attained even with a relatively short barrel, so that abnormal lengthening of the barrel is not necessary for satisfactory utilisation of the propelling charge and for attaining very high initial velocities.

The advantage of this construction is that by means of the firearm constructed on this principle, in comparison with the normal constructions, greater ballistic performances are secured, for the same length of barrel or the same weight of firearm, or the same ballistic performances are secured by employing shorter barrels or a lighter firearm. In addition, the manufacture of the barrel is just as simple as in the normal construction, because the bore of the barrel is cylindrical.

throughout :the entire length.

A further advantage is that the projectile leaving the barrel attachment is quite smooth, that is to say, it has no grooves and riing traces, so that the air-resistance of the projectile is thereby diminished. By exchanging the attachment, the same firearm can be used for projectiles of different iinal calibres, and after removing the attachment, the same rearm may be used for iiring normal heavy projectiles of a form and weight corresponding to the bore of the barrel. The same firearm may therefore be employed, for example, witli the attachment for firing light armorir-piercing projectiles of small calibre and high initial velocity or without attachment for firing heavy expanding projectiles of low initial velocity.

Some constructional examples are shown in the accompanying drawing.

Figure l is a section through the projectile,

Figure 2 is a section through the muzzle part of the barrel and the barrel attachment,

Figure 3 is a section of a modification of the y projectile in section.

Figures 6, 7 and 9 are sections of modications of the attachment, and.

Figures 8 and l0 are sections of further modiiications of the projectile.

In Figure 1, I is the body of the projectile. Its length, form and weight correspond to the final calibre a1 of the projectile, as possessed by the latter after leaving the barrel attachment, The guide bands or collars 2 and 2 correspond to the bore of the barrel a2. These bands are advantageously made of light plastic metal (for example dural or the like), in order that the energy required for their acceleration may be as smallv as possible.

Figure 2 shows a section through the barrel muzzle and the muzzle attachment. The barrel 3, over its entire length from the cartridge chamber to the muzzle, has a cylindrical bore of calibre a2 and a suitable number of riiiing grooves of constant pitch or a pitch varying as desired. The number ofthe rifiing grooves and their depth are selected as usual with regard to the material and the size of the sealing bands. 'I'he terminal angleof the rifling is such that the rotation necessary for stabilising the `projectile is imparted to the iinal form of the projectile with calibre ai. The attachment 4 is screwed or fixed in any other manner ,(for example by bayonet joint or the like) to the barrel 3 and in its interior a number of knife edges 5 are formed in continuation of the barrel 3. The inner diameter of these knife edges gradually diminishes from the original barrel calibre a2, to the calibre a1, so that the projectile entering the attachment 4 after leaving the barrel muzzle impacts against these knife edges, whereby the ange material is progressively cut away. After passing through the attachment, the projectile is entirely free from guide flanges and continues its further trajectory in a ballistically favourable form.

Figure 3 shows an armour-piercing projectile. It consists of the hardened steel core 6, welded or soldered to the tip of which is the cap 'l' of soft material (soft wrought iron, copper, brass or the like). On the rearward part of the core 6, which gently tapers conically to the rear, is mounted a sleeve 8 terminating in two or more guiding and sealing flanges 9 and 9'. 'Ihe sleeve 8 is advantageously made of material of low specie gravity ,and suicient strength, for example of dural or the like. After the projectile has passed through the barrel attachment, the entire sleeve 8 is cut to splinters by the knife edges of asiaeov of the calibre a2. After passing through the barrei, the guide flange I5 oi this projectile is comthe attachment, so that the projectile leaves the rearm as a smooth projectile of calibre ai. The armour piercing core in this projectile has the same calibre a1 so that weight of the projectile is used to the best advantage.

Figure 4 shows another alternative of the barrel attachment. The attachment II secured to the barrel I0 has a series of inserted rings I2 provided with knife edges. These knife edges may be interrupted in various ways, or as shown in Figure 5, a series of teeth may be provided. The attachment II may terminate in the cylindrical guide I3 for the projectile, whereby the latter is centered after the removal of the guide collars.

-The projectile shown in Figure 8 is made of soft deformable material, for example soft iron, copper, brass or the like. Its body I6 in the rear part passes from the calibre a1 to the ange I5 I pressed to the smooth nal form oi' calibre ai in the attachment Il according to Figure 'I and in the cylindrical bore I9. Advantageously, the guide ange is constructed so that the work of deformation necessary for compressing the flange I5 from the diameter a: to the diameter ai is as small as possible, and so that after deformation, thecavity of the projectile is lled as completely as possible.

Figure 6 shows an attachment 24| having a circular recess. The projectile constructed for example as shown in Figure 3, after passing through the barrel 2|! impacts with this flange 9 against the said circular recessv and the sleeve 8 is braked by its guide anges, while the projectile continues its path without sleeve. The bore a1 of this attachment is advantageously somewhat larger than the diameter of the projectile, so that the projectile passes through it with clearance and is not braked.

Figure 9 shows an attachment 23 inserted in the muzzle of the barrel 22 and secured, for example, by means of the screwthread 24.

Figure 10 shows another modification of an armour-piercing projectile, the hardened core 25` of which is pressed into the shell 26 of soft iron or other deformable material. During the passage of the projectile through the attachment, the guide of the projectile is deformed from the diameter an to the final diameter a1. l

We claim: v

l. A firearm having a ried barrel, and a bored out detachable attachment connected to the muzzle of the barrel, with the axis of the barrel and the axis of the bore of the attachment lying in alignment, a series of cutting rings within the attachment and a smooth-bored portion located between said cutting rings and the outlet end of the attachment, said cutting rings each having a smaller internal diameter than that of the barrel, whereby when the projectile is fired the forcing bands on the projectile are removed.

2. In combination with a rearm having a barrel with a riiied bore extending to its muzzle end, an attachment comprising a body detachably secured to said muzzle end, said body having a smooth outlet bore of lesser calibre than that of said rifle bore, and having a counterbore, and a plurality of disc-like rings located in said counterbore, said rings having bores with knife edges, the bores of the several rings progressively decreasing in diameter adjacent the muzzle of the barrel to the smooth outlet bore, the bores of the end rings corresponding respectively to said barrel bore and tol said smooth outlet bore.

3. In firearms, a barrel of the ordinary construction having a bore riiied to its outlet end combined with a detachable body havingia bore one portion of which is formed to t over the muzzle end of the firearm barrel, and another portion of which is of tapered form with the end of larger diameter adjacent the muzzle end of the barrel and its end of lesser diameter constituting the discharge end of the firearm, said tapered portion of the bore having its surface provided with a plurality of annular knife edges arranged in proximity with one another.

' EK JANnEK. FRANTrsEK KAREL JANEEK. 

